1. Field of the Invention
The invention relates to an equalizing tank (i.e., container) for a hydraulic motor vehicle brake system, with a housing comprising a housing upper part and a housing lower part, and with a device for monitoring the fluid level in the equalizing tank, said device comprising a switching unit which is fastened to the housing and has a plug-in connector and a contact carrier, a portion of which projects into a guide pipe which extends into an interior space of the tank, and a sensor element or switching element which is arranged on the contact carrier in the region of the guide pipe and which can be switched by means of a transmitter in a switching point at which the switching unit generates a signal for an electronic control unit.
2. Description of the Related Art
In a hydraulic motor vehicle brake system, the brake fluid required is located in the equalizing tank, with the device for monitoring the fluid level in the tank having, for example, a reed switch with a reed contact as the switching element and, for example, a magnetic transmitter as the transmitter. If the brake fluid level drops and the magnetic transmitter passes the switching point, the switching contacts of the reed switch close. This signal is evaluated in a control device and the driver of the motor vehicle can be warned by an optical and/or acoustic indication. In this case, it has to be ensured that the equalizing tank is always filled with a minimum of brake fluid in order not to jeopardize the operation of the brake system. As a rule, in order to monitor the fluid level in the tank, use is made of devices in which a float provided with a magnet switches the reed contact as soon as the float takes up a position (switching point) in which the fluid level in the tank falls below a defined minimum. A warning signal which can be perceived by the driver is triggered by the reed contact, whereupon suitable countermeasures can then be introduced.
An equalizing tank of the type in question is known, for example, from DE 37 16 135 A1 or DE 35 24 281 A1. A tab is fastened to the contact carrier of the known equalizing tank, said tab extending parallel to the longitudinal axis of the guide pipe and projecting into an inner slot of a radial projection of the guide pipe in order to be fastened in a predetermined position to projections of the guide pipe. The plug-in connector of the switching unit is provided in a plug-in connector housing which is welded to a side wall protruding from the housing upper part. This firstly requires extremely complicated installation. Secondly, the switching unit is not exchangeable as a result, and therefore, in the event of a defect, the entire equalizing tank has to be exchanged.
There are further disadvantages with regard to packaging and transportation of the known equalizing tank, since the switching unit protrudes from the upper side of the equalizing tank.